Difference between SS316L and SS316L Urea Grade

[octane]

What's the difference between 316L grade and 316L urea grade of stainless steel?
How the performance of both these grades vary?

[mechcolor]

The major differences are in Ni composition which is kept at 14% to make the Urea grade fully austenitic with carbon content restricted to 0.03%. Mo is also higher up to 2.7%. This how the corrosion resistance is enhanced than the normal 316L SS grade.
The performance of 316L urea grade is remarkable in Urea and its other corrosive intermediate compounds.
Another grade is used for extreme conditions in Urea service and that's 25Cr.22Ni.2Mo.

[octane]

Thanks... mechcolor.
What's the welding wire / electrode recommended to use for 316L urea grade?

[ashfaqanwer]

The recommended wire / electrode for welding of 316L urea grade is ER/E-310LMo (25Cr-20Ni-2Mo) with much lower ferrite content in as welded form.

[octane]

Thanks...
Can you please provide me a welding procedure for 316L urea grade...

[qaisarabbas]

in addition to Octane's question:
What is the theoretical corrosion rate both for SS-316L & SS-316LUG in a urea / carbamate service?

[arcpro]

Corrosion rate of 316L or 316L urea grade varies at different stages in Urea Piping. For a good comparison, you must see the results of Huey tests in accordance with ASTM 262 practice C for both the materials. For 316L UG, the corrosion rate in huey test stands at 0.6 mm/year and for 316L it would be above this value.
The ferrite content in 316L UG is restricted to 0.6% making it more resistant against intergranular corrosion.

in addition to Octane's question:
What is the theoretical corrosion rate both for SS-316L & SS-316LUG in a urea / carbamate service?

[ashfaqanwer]

Welding procedure attached.
Though this is for SS316L normal grade welding but you can straight away use that on SS316L UG welding also.

[qaisarabbas]

Thank you Arcpro

[octane]

Thanks Ashfaq.